SAN ANTONIO — Long-acting reversible contraception is more effective for pregnancy prevention than shorter-acting contraceptive methods and has the potential to reduce healthcare disparities and costs, yet is generally underused, pointed out a new military study.

The report published in the American Journal of Obstetrics and Gynecology suggested that an underserved population is United States military healthcare beneficiaries who have access to universal healthcare, including no-cost, no-copay contraception with unlimited method-switching.1

A study team led by San Antonio Military Medical Center researchers noted that efforts to increase long-acting reversible contraception initiation and continuation in this group could improve health outcomes and mitigate the serious consequences of unintended or mistimed pregnancy on readiness and cost to the military.

To determine long-acting reversible contraception initiation and continuation rates among the diverse military medical system population, the researchers conducted a retrospective cohort of more than 1.7 million women, aged 14-40 years, who were enrolled in the U.S. military healthcare system, TRICARE Prime, between October 2009 and September 2014.

During that time period, 188,533 women initiated long-acting reversible contraception, 74.6% of them selecting intrauterine contraceptives. Results indicated that method initiation rates remained relatively stable (41.7-50.1/1000 women/year) for intrauterine methods, although the rate for subdermal implants increased from 6.1-23.0/1000 women/year.

In an analysis of women who selected intrauterine contraceptives, 61.2% continued their method at 36 months, and 48.8% continued at 60 months. Among women who selected the implant, 32.0% continued their method at 36 months; however, 45.8% continued until 33 months (i.e., three months before the currently recommended expiration date).

The study found that, compared with intrauterine contraceptive users, implant users were more likely to discontinue their method during the 36 months after insertion for a hazard ratio of 1.59. The least likely age group to discontinue the implant before 36 months was adolescents aged 14-19 years. At the same time, women aged 35-40 years were the least likely to discontinue an intrauterine contraceptive before 60 months.

Overall, analysis indicated that contraceptive method discontinuation was most likely among women aged 20-24 years, implant users and women with method initiation in military clinics.

“In the U.S. military healthcare system, TRICARE Prime, the initiation of long-acting reversible contraception is low but increasing, and continuation rates are high,” study authors concluded. “This evidence supports long-acting reversible contraception as first-line recommendations for women of all ages who seek contraception.”